Bill Gates, the world's richest man, believes the US economy will not fall into a slump because technological progress will help it to grow, he said in an interview with a German newspaper on Thursday.

The Microsoft co-founder told Bild he believed the severe turbulence on the global markets sparked by concerns of a recession in the United States would calm down. "The US economy has been very strong in the last 10 to 15 years. Unfortunately I don't have a crystal ball to see into the next few years," Gates said. "But I am an optimist. The US economy could remain strong in the next few years because technological progress will propel it."

Gates denied he was anxiously keeping an eye on the Microsoft share price. "I'm no expert on shares, I'm a software person," he said. "I look at the share price every couple of weeks. "The important thing is that in the past it has gone up far more often than it has gone down." Gates was in Germany to announce that Microsoft will spend 235 million dollars (161 million euros) over the next five years to introduce more computers into classrooms. He was to address the World Economic Forum in Davos on Thursday. Gates led the Rich List compiled by Forbes magazine for the 13th year in 2007 with an estimated fortune of 56 billion dollars.